1. Field of the Invention
This invention relates to a battery module.
2. Description of Related Art
A flat thin cell which is formed by sealing a power generating element created by laminating positive and negative electrode plates with a package member such as a laminate film and deriving a platelike electrode tab to the exterior from the package member (hereinafter referred to as “flat cell”) has been known. In recent years, the practice of producing a battery module of high output and high capacity by stacking a plurality of such flat cells and, at the same time, electrically connecting the individual flat cells in series and/or in parallel has become popular (refer to Unexamined Japanese Patent Publication JP-A-2000-195480 and JP-A-2001-256934).
For the purpose of mounting the battery module on a vehicle, it is desirable to decrease the distance between adjacent flat cells to the fullest possible extent thereby compacting the whole volume of the battery module and as well forming a battery module structure that is less susceptible to the influence of the input of vibration. When a vibration is exerted to bear on the battery module, it may result in inducing concentration of stresses on the parts joining the electrode tabs.